Ecotypes: Considerations in Restoration
The University of Florida sent down a fleet of professors from their Consortium for Horticultural Application in Ecosystem Conservation. These passionate folks had some very interesting research to share as the crowd wrestled with both the ethical and the practical problems that restoration can pose. The Consortium works to provide science-based information to meet the needs of the native plant industry called in to supply the plants for restoration work.
Dr. Carrie Reinhardt Adams lead off with an explanation of ecotypes. She noted that there can be distinct and separate genetic composition within a plant species resulting from adaptation to local environmental conditions. Within each species then, some plants can be better adapted for certain conditions. Individuals are capable of interbreeding with other ecotypes within the species.
Questions arise when plants begin to be moved around by people; although certainly there are valid reasons for doing so. Substitutions of ecotypes can sometimes lead to genetic pollution. One way this type of pollution can happen is by replacement of local genotypes with less fit genotypes, leading to a decrease in genetic diversity. Lower genetic diversity, which makes plants more susceptible to disease, arises when plant material originates from just a few genotypes. One importance of diversity is that it provides the mechanism for evolution.
|Pickerelweed in bloom|
|Note corm on grass pink|
Kauth’s experiment centered around the question “Does growing season matter?” In Michigan, where the orchid is growing in a compressed season, Calopogon puts a lot of its early growth into the corm. In Florida, where the growing season for the orchid is 365 days a year, its corm is very small, more biomass is allocated to the leaf and the shoot.
Kauth put Calopogons from Michigan, South Carolina, North Florida and Central Florida into petri dishes in the greenhouse and grew them out under exactly the same conditions. What he found was that the orchids from the north, even in petri dishes, sent their biomass to the corm very early. Plants from SC in the dishes all the way to week 20 had very low biomass in the corm; they were growing more shoots, roots and leaves instead. The Michigan orchids at week 20 were almost almost all corm with very little growing shoot. The questions he next wants to answer is “Can the plants adapt to different ranges? What differences will be caused by new temperatures, seasons, and dormancy conditions?” Good questions.
|Wiregrass on the Wade Tract Preserve|
The results of his work, along with previous studies that presented evidence for local adaptation and phenotypic differences among populations, suggest that there is sufficient differentiation among populations of this species to warrant: (1) maintenance of the existing genetic diversity at individual sites, and (2) use of local seed and plant sources for conservation projects. But, he added, decisions about how material should be selected and moved are still in the formative stages.
|Sea-oats prevent erosion on beachfront|
Dune restoration, providing the first line of defense against storms, is a popular project these days, but the geographic source and genetic diversity of these plants present a real dilemma of choices. It turns out that there is a big difference between the ecotypes that grow on the east and west coasts of Florida, with no genetic crossover between the two sides. Along the east coast, where gene flow is fairly continuous, sea-oats are virtually the same ecotype. But along the west coast, significant variety is found. The west coast types were generally taller, with more leaves and different root structures. On one evaluation plot, after a three-year trial the west coast types exhibited a higher rate of survival. Dr. Kane noted that problems with seed availability, lack of consensus on a definition of the meaning of ‘local,’ and of course, cost, are among the present challenges to dune restoration. Perhaps even more significantly though, he stated that most dunes today are no longer “real” places or natural areas.
These fascinating presentations set the stage for break-out sessions on brainstorming solutions. The professors urged our group to help them understand the problems so they could focus research on helpful answers. The debate was loud and passionate; as you can imagine this room was full of people who care greatly about restoration and conservation. In fact, that might be one of the problems, see the post on Economics!
The time remaining was not nearly long enough, but some of the major problems were listed as;
- lack of flexibility on distance limitations for obtaining an ecotype match, as we have seen, geographic limitations may not be the defining paradigm
- lack of reliability on part of some providers, in other words, honesty sometimes a problem
- verification of source location sometimes not possible, for instance when big lots of plants from different places were mixed together
- insufficient time to obtain or grow the required plants was a major problem
One grower told of being asked to provide plants for a restoration project that needed to be installed in 9 days. This was upped by a grower who had been asked to provide material for an installation "tomorrow!"
The next big question of the day, “Where do we go from here?” was answered with these solutions:
- educate politicians
- better communication among those directly involved
- more native plant awareness